SELECT * FROM File_Attribute INNER JOIN Attribute ON FK_Attribute=PK_Attribute INNER JOIN AttributeType ON FK_AttributeType=PK_AttributeType WHERE FK_AttributeType IN ...(first join with Attribute table, then with AttributeType).

And I have tried installing LinuxMCE countless times to try and find a solution that works... In the end I gave up on LinuxMCE for now, and installed Pluto. There it works on the same hardware. The error must be in LinuxMCE.